Splayed cable guide for a medical instrument

ABSTRACT

An apparatus includes a housing, a cable guide, a first cable, and a second cable. The housing is coupled to a shaft of a medical instrument. The cable guide is coupled to the housing, and defines a shaft opening into a passageway defined by the shaft. A first guide groove and a second guide groove are defined by the cable guide, with each of the first guide groove and the second guide groove being splayed outward from the shaft opening. The first cable is routed within the first guide groove and through the shaft opening, and is configured to slide within the first guide groove. The second cable is routed within the second guide groove and through the shaft opening, and is configured to slide within the second guide groove.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/903,139 (filed Feb. 23, 2018), entitled “Splayed Cable Guide for aMedical Instrument,” which claims benefit of priority to U.S.Provisional Patent Application No. 62/463,105 (filed Feb. 24, 2017),entitled “Splayed Cable Guide,” each of which is incorporated herein byreference in its entirety.

BACKGROUND

The embodiments described herein relate to mechanisms for routingcables, more specifically to medical devices, and still morespecifically to endoscopic tools. More particularly, the embodimentsdescribed herein relate control cable routing in surgical instrumentsfor teleoperated medical devices.

Known techniques for Minimally Invasive Surgery (MIS) employ instrumentsto manipulate tissue that can be either manually controlled orcontrolled via computer-assisted teleoperation. Many known MISinstruments include a therapeutic or diagnostic end effector (e.g.,forceps, a cutting tool, or a cauterizing tool) mounted on a wristmechanism at the distal end of an extension (also referred to herein asthe main tube or shaft). The wrist mechanism may provide one or moreorientation, translation, or combinations of orientation and translationdegrees of freedom for the end effector. The end effector often has oneor more additional mechanical degrees of freedom, such as a scissors orgrip degree of freedom. In some instances, the wrist and end effectordegrees of freedom may be combined in a single mechanism, such as acombined yaw and grip degree of freedom.

To enable the desired movement of the wrist mechanism and end effector,known instruments include tension members (e.g., cables, tension bands)that extend through the main tube of the instrument and that connect thewrist mechanism to a transmission or actuator (also referred to hereinas a backend mechanism). The backend mechanism moves the cables tooperate the wrist mechanism. For robotic or teleoperated systems, thebackend mechanism is motor driven and can provide mechanical force ortorque input to the backend, and this force or torque is transmitted toone or more cables in order to operate the wrist or end effector degreesof freedom.

Known backend systems employ one or more pulleys to route the controlcables from the backend mechanism and into the shaft. Although knownarrangements reduce friction associated with cable movement and bends,the use of pulleys and shafts increases cost, complexity, and assemblytime. Thus, a need exists for mechanism for routing tension membersbetween the proximal end (i.e., the backend mechanism) and the distalend (i.e., the wrist mechanism) of medical instruments. A need alsoexists for improved cable routing mechanisms having reduced size,reduced part count, lower cost of materials, and which permit easyassembly including installation of tension members.

SUMMARY

This summary introduces certain aspects of the embodiments describedherein to provide a basic understanding. This summary is not anextensive overview of the inventive subject matter, and it is notintended to identify key or critical elements or to delineate the scopeof the inventive subject matter.

In some embodiments, an apparatus includes a housing, a cable guide, afirst cable, and a second cable. The housing is coupled to a shaft of amedical instrument. The cable guide is coupled to the housing anddefines a shaft opening into a passageway defined by the shaft. A firstguide groove and a second guide groove are defined by the cable guide,with each of the first guide groove and the second guide groove beingsplayed outward from the shaft opening. The first cable is routed withinthe first guide groove and through the shaft opening, and is configuredto slide within the first guide groove. The second cable is routedwithin the second guide groove and through the shaft opening and isconfigured to slide within the second guide groove.

In some embodiments, an apparatus includes a housing, a cable guide, afirst cable, and a second cable. The housing is coupled to a shaft of amedical instrument. The cable guide is coupled to the housing anddefines a shaft opening into a passageway defined by the shaft. Thecable guide includes a first guide surface and a second guide surface. Afirst guide groove is defined by the first guide surface, which includesa first bend portion transitioning from the first guide groove to theshaft opening. The first bend portion is characterized by a first bendradius about a first bend axis. A second guide groove is defined by thesecond guide surface, which includes a second bend portion transitioningfrom the second guide groove to the shaft opening. The second bendportion is characterized by a second bend radius about a second bendaxis. The second bend axis is nonparallel to the first bend axis. Thefirst cable is routed within the first guide groove and through theshaft opening. The second cable is routed within the second guide grooveand through the shaft opening.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a minimally invasive teleoperated medicalsystem according to an embodiment, being used to perform a medicalprocedure such as surgery.

FIG. 2 is a perspective view of a user control unit of the minimallyinvasive teleoperated surgery system shown in FIG. 1.

FIG. 3 is a perspective view of an optional auxiliary unit of theminimally invasive teleoperated surgery system shown in FIG. 1.

FIG. 4 is a front view of a manipulator unit, including a plurality ofinstruments, of the minimally invasive teleoperated surgery system shownin FIG. 1.

FIG. 5 is a diagrammatic top view of a portion of an instrument of asurgery system in a first position, according to an embodiment.

FIG. 6 is a diagrammatic side view of the portion of the instrumentshown in FIG. 5 taken along line X₁-X₁ in FIG. 5.

FIG. 7 is a diagrammatic top view of a portion of an instrument of asurgery system in a first position, according to an embodiment.

FIG. 8 is a diagrammatic side view of the portion of the instrumentshown in FIG. 7 taken along line X₁-X₁ in FIG. 7.

FIG. 9 is a diagrammatic side view of the portion of the instrumentshown in FIG. 7 taken along line X₂-X₂ in FIG. 7.

FIG. 10 is a perspective view of an instrument of a surgery system,according to an embodiment.

FIGS. 11 and 12 are enlarged perspective views of a transmission at theproximal end portion of the instrument shown in FIG. 10.

FIG. 13 is a top view of a cable guide and the cables of thetransmission shown in FIGS. 11 and 12.

FIGS. 14 and 15 are a top view (FIG. 14) and a top perspective view(FIG. 15) of the cable guide of the transmission shown in FIGS. 11 and12.

FIG. 16 is a bottom perspective view of the cable guide and the cablesof the transmission shown in FIGS. 11 and 12.

FIG. 17 is an exploded perspective view of the cable guide, the cables,and a portion of the shaft drive assembly of the transmission shown inFIGS. 11 and 12.

FIG. 18 is a perspective view of a transmission of an instrument,according to an embodiment.

FIG. 19 is a top perspective view of a cable guide of the transmissionshown in FIG. 18.

FIG. 20 is a bottom perspective view of the cable guide and the cablesof the transmission shown in FIG. 18.

FIG. 21 is a perspective view of a transmission of an instrument,according to an embodiment.

FIG. 22 is a top perspective view of a cable guide of the transmissionshown in FIG. 21.

FIG. 23 is a perspective exploded view of the cable guide of thetransmission shown in FIG. 21.

DETAILED DESCRIPTION

The embodiments described herein can advantageously be used in a widevariety of grasping, cutting, and manipulating operations associatedwith minimally invasive surgery. As described herein, the instrumentsinclude one or more cables (which act as tension members) that can bemoved to actuate the end effector with multiple degrees of freedom.Moreover, the cables can be routed via one or more cable guides of typesshown and described herein.

In some embodiments, an apparatus includes a housing, a cable guide, afirst cable, and a second cable. The housing is coupled to a shaft of amedical instrument. The cable guide is coupled to the housing anddefines a shaft opening into a passageway defined by the shaft. A firstguide groove and a second guide groove are defined by the cable guide,with each of the first guide groove and the second guide groove beingsplayed outward from the shaft opening. The first cable is routed withinthe first guide groove and through the shaft opening, and the firstcable is configured to slide within the first guide groove. The secondcable is routed within the second guide groove and through the shaftopening, and the second cable is configured to slide within the secondguide groove.

In some embodiments, an apparatus includes a housing, a cable guide, afirst cable, and a second cable. The housing is coupled to a shaft of amedical instrument. The cable guide is coupled to the housing anddefines a shaft opening into a passageway defined by the shaft. A firstguide groove and a second guide groove are defined by the housing. Afirst centerline of the first guide groove is nonparallel to a secondcenterline of the second guide groove. The first cable is routed withinthe first guide groove and through the shaft opening, and the firstcable is configured to slide within the first guide groove. The secondcable is routed within the second guide groove and through the shaftopening, and the second cable is configured to slide within the secondguide groove.

In some embodiments, an apparatus includes a housing, a cable guide, afirst cable, and a second cable. The housing is coupled to a shaft of amedical instrument. The cable guide is coupled to the housing anddefines a shaft opening into a passageway defined by the shaft. Thecable guide includes a first guide surface and a second guide surface. Afirst guide groove is defined by the first guide surface, which includesa first bend portion transitioning from the first guide groove to theshaft opening. The first bend portion is characterized by a first bendradius about a first bend axis. A second guide groove is defined by thesecond guide surface, which includes a second bend portion transitioningfrom the second guide groove to the shaft opening. The second bendportion is characterized by a second bend radius about a second bendaxis. The second bend axis is nonparallel to the first bend axis. Thefirst cable is routed within the first guide groove and through theshaft opening. The second cable is routed within the second guide grooveand through the shaft opening.

As used herein, the term “about” when used in connection with areferenced numeric indication means the referenced numeric indicationplus or minus up to 10 percent of that referenced numeric indication.For example, the language “about 50” covers the range of 45 to 55.Similarly, the language “about 5” covers the range of 4.5 to 5.5.

The term “flexible” in association with a part, such as a mechanicalstructure, component, or component assembly, should be broadlyconstrued. In essence, the term means the part can be repeatedly bentand restored to an original shape without harm to the part. Certainflexible components can also be resilient. For example, a component(e.g., a flexure) is said to be resilient if possesses the ability toabsorb energy when it is deformed elastically, and then release thestored energy upon unloading (i.e., returning to its original state).Many “rigid” objects have a slight inherent resilient “bendiness” due tomaterial properties, although such objects are not considered “flexible”as the term is used herein.

A flexible part may have infinite degrees of freedom (DOF's).Flexibility is an extensive property of the object being described, andthus is dependent upon the material from which the object is formed aswell as certain physical characteristics of the object (e.g.,cross-sectional shape, length, boundary conditions, etc.). For example,the flexibility of an object can be increased or decreased byselectively including in the object a material having a desired modulusof elasticity, flexural modulus and/or hardness. The modulus ofelasticity is an intensive property of (i.e., is intrinsic to) theconstituent material and describes an object's tendency to elastically(i.e., non-permanently) deform in response to an applied force. Amaterial having a high modulus of elasticity will not deflect as much asa material having a low modulus of elasticity in the presence of anequally applied stress. Thus, the flexibility of the object can bedecreased, for example, by introducing into the object and/orconstructing the object of a material having a relatively high modulusof elasticity. Examples of such parts include closed, bendable tubes(made from, e.g., NITINOL®, polymer, soft rubber, and the like), helicalcoil springs, etc. that can be bent into various simple or compoundcurves, often without significant cross-sectional deformation.

Other flexible parts may approximate such an infinite-DOF part by usinga series of closely spaced components that are similar to a serialarrangement of short, connected links as snake-like “vertebrae.” In sucha vertebral arrangement, each component is a short link in a kinematicchain, and movable mechanical constraints (e.g., pin hinge, cup andball, live hinge, and the like) between each link may allow one (e.g.,pitch) or two (e.g., pitch and yaw) DOFs of relative movement betweenthe links. A short, flexible part may serve as, and be modeled as, asingle mechanical constraint (a joint) that provides one or more DOF'sbetween two links in a kinematic chain, even though the flexible partitself may be a kinematic chain made of several coupled links havingmultiple DOFs, or an infinite-DOF link.

As used in this specification and the appended claims, the word “distal”refers to direction towards a work site, and the word “proximal” refersto a direction away from the work site. Thus, for example, the end of atool that is closest to the target tissue would be the distal end of thetool, and the end opposite the distal end (i.e., the end manipulated bythe user or coupled to the actuation shaft) would be the proximal end ofthe tool.

Further, specific words chosen to describe one or more embodiments andoptional elements or features are not intended to limit the invention.For example, spatially relative terms—such as “beneath”, “below”,“lower”, “above”, “upper”, “proximal”, “distal”, and the like—may beused to describe the relationship of one element or feature to anotherelement or feature as illustrated in the figures. These spatiallyrelative terms are intended to encompass different positions (i.e.,translational placements) and orientations (i.e., rotational placements)of a device in use or operation in addition to the position andorientation shown in the figures. For example, if a device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be “above” or “over” the other elementsor features. Thus, the term “below” can encompass both positions andorientations of above and below. A device may be otherwise oriented(e.g., rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly. Likewise,descriptions of movement along (translation) and around (rotation)various axes includes various spatial device positions and orientations.The combination of a body's position and orientation define the body'spose.

Similarly, geometric terms, such as “parallel”, “perpendicular”,“round”, or “square”, are not intended to require absolute mathematicalprecision, unless the context indicates otherwise. Instead, suchgeometric terms allow for variations due to manufacturing or equivalentfunctions. For example, if an element is described as “round” or“generally round,” a component that is not precisely circular (e.g., onethat is slightly oblong or is a many-sided polygon) is still encompassedby this description.

In addition, the singular forms “a”, “an”, and “the” are intended toinclude the plural forms as well, unless the context indicatesotherwise. The terms “comprises”, “includes”, “has”, and the likespecify the presence of stated features, steps, operations, elements,components, etc. but do not preclude the presence or addition of one ormore other features, steps, operations, elements, components, or groups.

Unless indicated otherwise, the terms apparatus, medical device,instrument, and variants thereof, can be interchangeably used.

Aspects of the invention are described primarily in terms of animplementation using a da Vinci® Surgical System, commercialized byIntuitive Surgical, Inc. of Sunnyvale, Calif. Examples of such surgicalsystems are the da Vinci Xi® Surgical System (Model IS4000) and the daVinci Si® Surgical System (Model IS3000). Knowledgeable persons willunderstand, however, that inventive aspects disclosed herein may beembodied and implemented in various ways, including computer-assisted,non-computer-assisted, and hybrid combinations of manual andcomputer-assisted embodiments and implementations. Implementations on daVinci® Surgical Systems (e.g., the Model IS4000, the Model IS3000, theModel IS2000, the Model IS1200) are merely presented as examples, andthey are not to be considered as limiting the scope of the inventiveaspects disclosed herein. As applicable, inventive aspects may beembodied and implemented in both relatively smaller, hand-held,hand-operated devices and relatively larger systems that have additionalmechanical support.

FIG. 1 is a plan view illustration of a computer-assisted teleoperationsystem. Shown is a medical device, which is a Minimally Invasive RoboticSurgical (MIRS) system 1000 (also referred to herein as a minimallyinvasive teleoperated surgery system), used for performing a minimallyinvasive diagnostic or surgical procedure on a Patient P who is lying onan Operating table 1010. The system can have any number of components,such as a user control unit 1100 for use by a surgeon or other skilledclinician S during the procedure. The MIRS system 1000 can furtherinclude a manipulator unit 1200 (popularly referred to as a surgicalrobot), and an optional auxiliary equipment unit 1150. The manipulatorunit 1200 can include an arm assembly 1300 and a tool assembly removablycoupled to the arm assembly. The manipulator unit 1200 can manipulate atleast one removably coupled tool assembly 1400 (also referred to hereinas a “tool”) through a minimally invasive incision in the body ornatural orifice of the patient P while the surgeon S views the surgicalsite and controls movement of the tool 1400 through control unit 1100.An image of the surgical site is obtained by an endoscope (not shown),such as a stereoscopic endoscope, which can be manipulated by themanipulator unit 1200 to orient the endoscope. The auxiliary equipmentunit 1150 can be used to process the images of the surgical site forsubsequent display to the Surgeon S through the user control unit 1100.The number of tools 1400 used at one time will generally depend on thediagnostic or surgical procedure and the space constraints within theoperating room, among other factors. If it is necessary to change one ormore of the instruments 1400 being used during a procedure, an assistantremoves the instrument 1400 from the manipulator unit 1200 and replacesit with another instrument 1400 from a tray 1020 in the operating room.Although shown as being used with the instruments 1400, any of theinstruments described herein can be used with the MIRS 1000.

FIG. 2 is a perspective view of the control unit 1100. The user controlunit 1100 includes a left eye display 1112 and a right eye display 1114for presenting the surgeon S with a coordinated stereo view of thesurgical site that enables depth perception. The user control unit 1100further includes one or more input control devices 1116, which in turncause the manipulator unit 1200 (shown in FIG. 1) to manipulate one ormore tools. The input control devices 1116 provide at least the samedegrees of freedom as instruments 1400 with which they are associated toprovide the surgeon S with telepresence, or the perception that theinput control devices 1116 are integral with (or are directly connectedto) the instruments 1400. In this manner, the user control unit 1100provides the surgeon S with a strong sense of directly controlling theinstruments 1400. To this end, position, force, and tactile feedbacksensors (not shown) may be employed to transmit position, force, andtactile sensations from the instruments 1400 back to the surgeon's handsthrough the input control devices 1116.

The user control unit 1100 is shown in FIG. 1 as being in the same roomas the patient so that the surgeon S can directly monitor the procedure,be physically present if necessary, and speak to an assistant directlyrather than over the telephone or other communication medium. In otherembodiments, however, the user control unit 1100 and the surgeon S canbe in a different room, a completely different building, or other remotelocation from the patient allowing for remote surgical procedures.

FIG. 3 is a perspective view of the auxiliary equipment unit 1150. Theauxiliary equipment unit 1150 can be coupled with the endoscope (notshown) and can include one or more processors to process captured imagesfor subsequent display, such as via the user control unit 1100, or onanother suitable display located locally and/or remotely. For example,where a stereoscopic endoscope is used, the auxiliary equipment unit1150 can process the captured images to present the surgeon S withcoordinated stereo images of the surgical site via the left eye display1112 and the right eye display 1114. Such coordination can includealignment between the opposing images and can include adjusting thestereo working distance of the stereoscopic endoscope. As anotherexample, image processing can include the use of previously determinedcamera calibration parameters to compensate for imaging errors of theimage capture device, such as optical aberrations.

FIG. 4 shows a front perspective view of the manipulator unit 1200. Themanipulator unit 1200 includes the components (e.g., arms, linkages,motors, sensors, and the like) to provide for the manipulation of theinstruments 1400 and an imaging device (not shown), such as astereoscopic endoscope, used for the capture of images of the site ofthe procedure. Specifically, the instruments 1400 and the imaging devicecan be manipulated by teleoperated mechanisms having a number of joints.Moreover, the instruments 1400 and the imaging device are positioned andmanipulated through incisions or natural orifices in the patient P in amanner such that a kinematic remote center of motion is maintained atthe incision or orifice. In this manner, the incision size can beminimized.

FIGS. 5 and 6 are diagrammatic illustrations of various portions of atransmission 2700, according to an embodiment. The transmission 2700 canbe included in any of the instruments shown and described herein (e.g.,the instrument 4400) and can function as an actuator to move one or moretensions members (e.g., the first cable 2420 and the second cable 2430)to actuate any suitable end effector. In some embodiments, thetransmission 2700 or any of the components therein are optionally partsof a surgical system that performs minimally invasive surgicalprocedures and which can include a manipulator unit, a series ofkinematic linkages, a series of cannulas, or the like. The transmission2700 (and any of the instruments described herein) can be used in anysuitable surgical system, such as the MIRS system 1000 shown anddescribed above. The transmission 2700 includes a chassis 2760, a firstactuator 2710, a second actuator 2720, and a cable guide 2800.

The chassis 2760 (which functions as a housing) provides the structuralsupport for mounting and aligning the components of the transmission2700. For example, as shown in FIG. 6, the chassis 2760 is coupled to ashaft 2410 of a medical instrument. The shaft 2410 can be any suitableelongated shaft that couples a wrist assembly, end effector, or othercomponent (not shown) to the transmission 2700. Specifically, the shaft2410 includes a proximal end portion that is coupled to the chassis2760. The shaft 2410 defines at least one passageway 2413 through whichthe first cable 2420, the second cable 2430, and other components (e.g.,energized electrical wires, ground wires, or the like, not shown inFIGS. 5 and 6) can be routed from the transmission 2700 towards a wristassembly, end effector, or other component. Although shown as includinga single passageway 2413 that defines a shaft center line CL_(SH), inother embodiments, the shaft 2410 can define multiple passageways.Moreover, although the chassis 2760 is shown as defining an openingwithin which the proximal end portion of an instrument shaft 2410 ismounted, in other embodiments, the shaft 2410 can be coupled to thechassis 2760 by any suitable mechanism (e.g., a flange connection).

The chassis 2760 also provides support structure and mounting structureto which the first actuator 2710 and the second actuator 2720 aremounted. In addition to providing mounting support for the internalcomponents of the transmission 2700, the chassis 2760 can also includeexternal features (not shown, but which can be recesses, clips, etc.)that interface with a docking port of a drive device (not shown). Thedrive device can be, for example, a computer-assisted teleoperatedsurgical system that can receive the transmission 2700 and manipulatethe transmission 2700 to perform various surgical operations. In otherembodiments, the drive device can be an assembly system that can receiveand manipulate the transmission 2700 to perform various assemblyoperations.

The first actuator 2710 is any suitable actuator that can apply a forceto or move the first cable 2420 (see the arrow AA in FIG. 6 showingmovement of the first cable 2420). Similarly, the second actuator 2720is any suitable actuator that can apply a force to or move the secondcable 2430. Movement of the first cable 2420 and the second cable 2430within the transmission 2700 and through the shaft 2410 can produce thedesired movement (e.g., rotating, gripping, etc.) of the wrist assembly,end effector, or other component coupled to the distal end portion ofthe shaft 2410. The first actuator 2710 and the second actuator 2720 caneach be any suitable mechanism or assembly for applying a force to ormoving the cables. For example, in some embodiments, the first actuator2710, the second actuator 2720, or both can be a motor-driven rotatingactuator (e.g., a capstan) that winds or unwinds a cable to cause thedesired movement of the cable. For example, in some embodiments, thefirst actuator 2710, the second actuator 2720, or both can include anyof the capstan assemblies or components described in U.S. Pat. No.9,204,923 B2 (filed Jul. 16, 2008), entitled “Medical InstrumentElectronically Energized Using Drive Cables,” which is incorporatedherein by reference in its entirety. In other embodiments, the firstactuator 2710, the second actuator 2720, or both can include a linearactuator that pulls in or releases a cable. For example, in someembodiments, the first actuator 2710, the second actuator 2720, or bothcan be a linear actuator of the types described in U.S. PatentApplication Pub. No. US2015/0047454 A1 (filed Aug. 15, 2014), entitled“Lever Actuated Gimbal Plate,” or U.S. Pat. No. 6,817,974 B2 (filed Jun.28, 2001), entitled “Surgical Tool Having Positively PositionableTendon-Actuated Multi-Disk Wrist Joint,” each of which is incorporatedherein by reference in its entirety.

The cable guide 2800 is coupled to the housing 2760 and defines a shaftopening 2821, a first guide groove 2831, and a second guide groove 2832.The shaft opening 2821 is defined by an inner surface 2820 of the cableguide 2800 and opens into the passageway 2413 of the shaft 2410. Asshown in FIG. 6, the shaft opening 2821 defines an opening center lineCL_(OP). Although shown as being parallel to, but noncoaxial with theshaft center line CL_(SH), in other embodiments, the opening center lineCL_(OP) can be coaxial with (i.e., aligned with) the shaft center lineCL_(SH). In other embodiments, however, the opening center line CL_(OP)can be nonparallel to the shaft center line CL_(SH). The shaft opening2821 need not be circular, but can have any suitable shape, as shown.

The first guide groove 2831 is defined by a first guide surface 2841 ofthe cable guide 2800 and defines a first guide center line CL₁. Asshown, the first cable 2420 is routed within the first guide groove2831, through the shaft opening 2821, and towards the shaft passageway2413. The second guide groove 2832 is defined by a second guide surface2842 of the cable guide 2800 and defines a second guide center line CL₂.The second cable 2430 is routed within the second guide groove 2832,through the shaft opening 2821 and towards the shaft passageway 2413. Asshown in FIG. 5, the first guide groove 2831 and the second guide groove2832 are splayed outward from the shaft opening 2821. Similarly stated,the first guide groove 2831 and the second guide groove 2832 are spreadout apart from the shaft opening 2821. Said yet another way, the firstguide groove 2831 and the second guide groove 2832 extend from the shaftopening 2821 and are nonparallel to each other. Specifically, the firstguide center line CL₁ is nonparallel to the second guide center lineCL₂. As shown in FIG. 5, the first guide center line CL₁ and the secondguide center line CL₂ define a splay angle θ. The splay angle θ can beany suitable value that facilitates alignment between the first actuator2710 and the shaft opening 2821 and between the second actuator 2720 andthe shaft opening 2821. The splay angle θ can be, for example, between 5degrees and 60 degrees, between 10 degrees and 45 degrees, or between 15degrees and 30 degrees.

Although shown as being linear, in other embodiments, the first guidegroove 2831, the second guide groove 2832, and any of the guide groovesdescribed herein can be any suitable shape that allows for the firstcable 2420 to be routed from the first actuator 2710 into the shaftopening 2821 and allows for the second cable 2430 to be routed thesecond actuator 2720 into the shaft opening 2821. In this manner, thefirst cable 2420 and the second cable 2430 can be routed into thedesired position within the shaft opening 2821 (e.g., relative to theopening center line CL_(OP) or the shaft center line CL_(SH)).Specifically, the first cable 2420 and the second cable 2430 can bepositioned within the shaft passageway 2413 spaced apart from the shaftcenter line CL_(SH) and at different radial or circumferential positionswithin the shaft passageway 2413. This arrangement can reduce thelikelihood that the first cable 2420 will become entangled with (e.g.,twisted about) the second cable 2430 within shaft 2410. For example, insome embodiments, the shaft 2410 can be configured to rotate about theshaft center line CL_(SH) (e.g., in cases where shaft and portions ofcables therein rotate about the shaft axis (which functions as a rollaxis; the term roll is arbitrary). The cable guide 2800, andspecifically the first guide groove 2831 and the second guide groove2832 facilitate low-friction operation, including roll operation, bymaintaining the first cable 2420 and the second cable 2430 within theshaft 2410 in their desired locations.

Referring to FIG. 6, the first guide center line CL₁ is nonparallel tothe opening center line CL_(OP). To facilitate this transition (or bendin the first cable 2420), the first guide surface 2841 includes a bendportion 2846 that transitions the first guide groove 2831 into the shaftopening 2821. The angle β between the first guide center line CL₁ andthe opening center line CL_(OP) (referred to as the bend angle) can beany suitable value. For example, in some embodiments, the bend angle βcan be greater than 45 degrees. In other embodiments, the bend angle βcan be greater than 60 degrees. In yet other embodiments, the bend angleβ can be greater than 75 degrees.

In use, when the first actuator 2710 actuates the first cable 2420(e.g., to cause movement of the first cable 2420), the first cable 2420slides within the first guide groove 2831. Similarly, when the secondactuator 2720 actuates the second cable 2430 (e.g., to cause movement ofthe second cable 2430), the second cable 2430 slides within the secondguide groove 2832. Thus, the first cable 2420 slides against the firstguide surface 2841 (including the bend portion 2846) and the secondcable 2430 slides against the second guide surface 2842. In someembodiments, any of the guide surfaces described herein can beconstructed from a low-friction material that reduces the frictionallosses between the cables and the cable guide. For example, in someembodiments, the cable guide 2800 (and any of the cable guides describedherein) can be monolithically constructed from a low friction material.Such materials can include, for example, polyether ether ketone (PEEK)filled with at least one of a glass material or polytetrafluoroethylene(PTFE). In some embodiments, the cable guide 2800 (and any of the cableguides described herein) can be monolithically constructed from anysuitable material (e.g., polymer, metal, composite) and can include afriction-reducing coating on the guide surfaces (e.g., the first guidesurface 2841, including the bend portion 2846). In yet otherembodiments, the cable guide 2800 (and any of the cable guides describedherein) can be constructed from separate components that are assembledto form the cable guide 2800. For example, in some embodiments, thecable guide 2800 (and any of the cable guides described herein) caninclude a bend portion (e.g., the bend portion 2846) that is a separatecomponent coupled to the remainder of the cable guide. Although the bendportion 2846 is shown and described as being in a fixed position (i.e.,it does not move) relative the cable guide 2800, in other embodiments,the cable guide 2800 (and any of the cable guides described herein) caninclude one or more bearings or rollers captively coupled within a guidegroove (e.g., the first guide groove 2831) to reduce the friction whenthe cable slides against the cable guide.

In some embodiments, a cable guide can include multiple guide grooves,each having a bend portion that transitions each guide groove into ashaft opening, a shaft passageway, or both a shaft opening or a shaftpassageway. Moreover, in such embodiments, the bend portions can form acurvature about a bend axis and each bend axis can be nonparallel toanother bend axis. For example, FIGS. 7-9 are diagrammatic illustrationsof various portions of a transmission 3700, according to an embodiment.The transmission 3700 can be included in any of the instruments shownand described herein (e.g., the instrument 4400) and can function as anactuator to move one or more tensions members (e.g., the first cable3420, see FIG. 8, and the second cable 3430, see FIG. 9) to actuate anysuitable end effector. In some embodiments, the transmission 3700 or anyof the components therein are optionally parts of a surgical system thatperforms minimally invasive surgical procedures and which can include amanipulator unit, a series of kinematic linkages, a series of cannulas,or the like. The transmission 3700 (and any of the instruments describedherein) can be used in any suitable surgical system, such as the MIRSsystem 1000 shown and described above. The transmission 3700 includes achassis 3760 and a cable guide 3800.

The chassis 3760 (which functions as a housing) provides the structuralsupport for mounting and aligning the components of the transmission3700. For example, as shown in FIGS. 8 and 9, the chassis 3760 iscoupled to a shaft 3410 of a medical instrument. The shaft 3410 can beany suitable elongated shaft that couples a wrist assembly, endeffector, or other component (not shown) to the transmission 3700.Specifically, the shaft 3410 includes a proximal end portion that iscoupled to the chassis 3760. The shaft 3410 defines at least onepassageway 3413 through which the first cable 3420, the second cable3430, and other components (e.g., energized electrical wires, groundwires, or the like, not shown in FIGS. 7-9) can be routed from thetransmission 3700 towards a wrist assembly, end effector, or othercomponent. Although shown as including a single passageway 3413 thatdefines a shaft center line CL_(SH), in other embodiments, the shaft3410 can define multiple passageways. Moreover, although the chassis3760 is shown as defining an opening within which the proximal endportion of an instrument shaft 3410 is mounted, in other embodiments,the shaft 3410 can be coupled to the chassis 3760 by any suitablemechanism (e.g., a flange connection).

The chassis 3760 also provides support structure and mounting structureto which one or more actuators (not shown, but which can be similar tothe first actuator 2710 or the second actuator 2720 described above).Specifically, the one or more actuators can be any suitable actuatorthat can apply a force to or move the first cable 3420, the second cable3430, or both. Movement of the first cable 3420 is shown by the arrow BBin FIG. 8, and movement of the second cable 3430 is shown by the arrowCC in FIG. 9. In addition to providing mounting support for the internalcomponents of the transmission 3700, the chassis 3760 can also includeexternal features (not shown, but which can be recesses, clips, etc.)that interface with a docking port of a drive device (not shown). Thedrive device can be, for example, a computer-assisted teleoperatedsurgical system that can receive the transmission 3700 and manipulatethe transmission 3700 to perform various surgical operations. In otherembodiments, the drive device can be an assembly system that can receiveand manipulate the transmission 3700 to perform various assemblyoperations.

The cable guide 3800 is coupled to the housing 3760 and defines a shaftopening 3821, a first guide groove 3831, and a second guide groove 3832.The cable guide 3800 can be coupled to the housing 3760 by any suitablemechanism. For example, as shown the cable guide 3800 includes amounting portion 3810 that is coupled to the housing 3760. The mountingportion 3810 can be any portion or structure that engages the housing3760, such as a protrusion, a recess, a shoulder, or a fastener. In thismanner, the mounting portion 3810 indexes the cable guide 3800 to thehousing 3760 (and therefore the shaft 3410) to ensure that the shaftopening 3821 is aligned with the shaft 3410 as desired.

The shaft opening 3821 is defined by an inner surface 3820 of the cableguide 3800 and opens into the passageway 3413 of the shaft 3410. Asshown in FIGS. 8 and 9, the shaft opening 3821 defines an opening centerline CL_(OP). Although shown as being parallel to, but noncoaxial withthe shaft center line CL_(SH), in other embodiments, the opening centerline CL_(OP) can be coaxial with (i.e., aligned with) the shaft centerline CL_(SH). In other embodiments, however, the opening center lineCL_(OP) can be nonparallel to the shaft center line CL_(SH). The shaftopening 3821 need not be circular, but can have any suitable shape, asshown.

Referring to FIG. 8, the first guide groove 3831 is defined by a firstguide surface 3841 of the cable guide 3800 and defines a first guidecenter line CL₁. As shown, the first cable 3420 is routed within thefirst guide groove 3831, through the shaft opening 3821, and towards theshaft passageway 3413. The first guide surface 3841 includes a firstbend portion 3846 transitioning from the first guide groove 3831 intothe shaft opening 3821. The first bend portion 3846 is characterized bya first bend radius R₁ about a first bend axis AB₁. The first bend axisAB₁ is offset from the mounting portion 3810 by a first distance.Specifically, the first bend axis AB₁ is offset from the mountingportion 3810 by a first vertical distance D_(Y1) and a first horizontaldistance D_(X1). In this manner, the location of the first bend axis AB₁relative to the shaft passageway 3413 is indexed. The bend angle (i.e.,the angle between the first guide center line CL₁ and the opening centerline CL_(OP)) can be any suitable value. For example, in someembodiments, the bend angle can be greater than 45 degrees. In otherembodiments, the bend angle can be greater than 60 degrees. In yet otherembodiments, the bend angle can be greater than 75 degrees.

Referring to FIG. 9, the second guide groove 3832 is defined by a secondguide surface 3842 of the cable guide 3800 and defines a second guidecenter line CL₂. As shown, the second cable 3430 is routed within thesecond guide groove 3832, through the shaft opening 3821 and towards theshaft passageway 3413. The second guide surface 3842 includes a secondbend portion 3847 transitioning from the second guide groove 3832 intothe shaft opening 3821. The second bend portion 3847 is characterized bya second bend radius R₂ about a second bend axis AB₂. The second bendaxis AB₂ is offset from the mounting portion 3810 by a first distance.Specifically, the second bend axis AB₂ is offset from the mountingportion 3810 by a second vertical distance D_(Y2) and a secondhorizontal distance D_(X2). In this manner, the location of the secondbend axis AB₂ relative to the shaft passageway 3413 is indexed. The bendangle (i.e., the angle between the second guide center line CL₂ and theopening center line CL_(OP)) can be any suitable value. For example, insome embodiments, the bend angle can be greater than 45 degrees. Inother embodiments, the bend angle can be greater than 60 degrees. In yetother embodiments, the bend angle can be greater than 75 degrees.

As shown in FIG. 7, the first bend axis AB₁ is nonparallel to the secondbend axis AB₂. This arrangement allows the first guide groove 3831 andthe second guide groove 3832 to be splayed outward from the shaftopening 3821. Moreover, in some embodiments, the first bend axis AB₁ andthe second bend axis AB₂ can be offset from the mounting surface bydifferent distances. For example, in some embodiments, the firstvertical distance D_(Y1) can be greater than the second verticaldistance D_(Y2). With this arrangement, the first bend portion 3846 ispositioned higher than (relative to the shaft 3410) than the second bendportion 3847. In other embodiments, the first horizontal distance D_(X1)can be greater than the second horizontal distance D_(X2). With thisarrangement, the first bend portion 3846 is positioned closer towardsthe shaft center line CL_(SH) than is the second bend portion 3847. Inthis manner, the first cable 3420 and the second cable 3430 can berouted into the desired position within the shaft opening 3821 (e.g.,relative to the opening center line CL_(OP) or the shaft center lineCL_(SH)). Specifically, the first cable 3420 and the second cable 3430can be positioned within the shaft passageway 3413 spaced apart from theshaft center line CL_(SH) and at different radial or circumferentialpositions within the shaft passageway 3413. This arrangement can reducethe likelihood that the first cable 3420 will become entangled with(e.g., twisted about) the second cable 3430 within shaft 3410. Forexample, in some embodiments, the shaft 3410 can be configured to rotateabout the shaft center line CL_(SH) (e.g., in cases where shaft andportions of cables therein rotate about the shaft axis (which functionsas a roll axis; the term roll is arbitrary). The cable guide 3800, andspecifically the first guide groove 3831 and the second guide groove3832 facilitates low-friction operation, including roll operation, bymaintaining the first cable 3420 and the second cable 3430 within theshaft 3410 in their desired locations.

In some embodiments, the first bend radius R₁ can be the same size asthe second bend radius R₂. In other embodiments, the first bend radiusR₁ can be a different size as the second bend radius R₂. Moreover, insome embodiments, either of the first bend portion 3846 or the secondbend portion 3847 can be characterized by any suitable curved shape,including a non-circular shape that is constructed from multipledifferent bend radii.

In use, when the first actuator 3710 actuates the first cable 3420(e.g., to cause movement of the first cable 3420, as shown by the arrowBB), the first cable 3420 slides within the first guide groove 3831.Similarly, when the second actuator 3720 actuates the second cable 3430(e.g., to cause movement of the second cable 3430, as shown by the arrowCC), the second cable 3430 slides within the second guide groove 3832.Thus, the first cable 3420 slides against the first guide surface 3841(including the first bend portion 3846), and the second cable 3430slides against the second guide surface 3842 (including the second bendportion 3847).

Although the transmission 2700 and the transmission 3700 are each shownand described as including only two tension members (e.g., the firstcable 2420 and the second cable 2430), in other embodiments, atransmission or an instrument can include any suitable number of tensionmembers. For example, in some embodiments, an instrument can includefour tension members (or portions of tension members) or six tensionmembers (or portions of tension members). For example, FIGS. 10-17 arevarious views of an instrument 4400 (and portions of the instrument4400), according to an embodiment. In some embodiments, the instrument4400 or any of the components therein are optionally parts of a surgicalassembly that performs minimally invasive surgical procedures and whichcan include a manipulator unit, a series of kinematic linkages, a seriesof cannulas, or the like. The instrument 4400 (and any of theinstruments described herein) can be used in any suitable surgicalsystem, such as the MIRS system 1000 shown and described above. Theinstrument 4400 includes a transmission 4700 (that can function as anactuator mechanism), an instrument shaft 4410, a wrist assembly 4500,and an end effector 4460.

Referring to FIG. 11, the instrument 4400 also includes a first cable4420 (which functions as a tension member), a second cable 4430 (whichfunctions as a tension member), a third cable 4440 (which functions as atension member), and a fourth cable 4450 (which functions as a tensionmember) that couple the transmission 4700 to the wrist assembly 4500.The instrument 4400 is configured such that movement of the tensionmembers can produce rotation of the wrist assembly 4500 (i.e., pitchrotation), yaw rotation of the end effector 4460, grip rotation of thetool members of the end effector 4460 about the yaw axis, or anycombination of these movements. Changing the pitch, yaw, or grip of theinstrument 4400 can be performed by manipulating the four tensionmembers.

The transmission 4700 produces movement of each of the first tensionmember 4420 and the second tension member to produce the desiredmovement (pitch, yaw, or grip) at the wrist assembly 4500. Specifically,the transmission 4700 includes components and controls to move some ofthe tension members in a proximal direction (i.e., to pull in certaintension members) while simultaneously allowing the distal movement(i.e., releasing or “paying out”) of other of the tension members. Inthis manner, the transmission 4700 can maintain the desired tensionwithin the tension members, and, in some embodiments, can ensure thatthe lengths of the tension members are conserved (i.e., moved in equalamounts) during the entire range of motion of the wrist assembly 4500.

The transmission 4700 includes a chassis 4760, a first capstan assembly4710, a second capstan assembly 4720, a third capstan assembly 4730, afourth capstan assembly 4740, a roll actuator 4750, and a cable guide4800. The chassis 4760 (which functions as a housing) provides thestructural support for mounting and aligning the components of thetransmission 4700. For example, as shown in FIG. 11, the chassis 4760defines a first opening within which the proximal end portion 4411 ofthe shaft 4410 is mounted, and multiple second openings within which thecapstan assemblies are mounted. The chassis 4760 includes an upperhousing 4765 that provides additional mounting surfaces and support(e.g., for the capstan assemblies).

The shaft 4410 can be any suitable elongated shaft that couples thewrist assembly 4500 and the end effector 4460 to the transmission 4700.Specifically, the shaft 4410 includes a proximal end portion 4411 thatis coupled to the chassis 4760. The shaft 4410 defines at least onepassageway through which the first cable 4420, the second cable 4430,the third cable 4440, the fourth cable 4450, and other components (e.g.,energized electrical wires, ground wires, or the like, not shown) can berouted from the transmission 4700 towards the wrist assembly 4500.Moreover, although the chassis 4760 is shown as defining an openingwithin which the proximal end portion of an instrument shaft 4410 ismounted, in other embodiments, the shaft 4410 can be coupled to thechassis 4760 by any suitable mechanism (e.g., a flange connection).

In addition to providing mounting support for the internal components ofthe transmission 4700, the chassis 4760 can also include externalfeatures (not shown, but which can be recesses, clips, etc.) thatinterface with a docking port of a drive device (not shown). The drivedevice can be, for example, a computer-assisted teleoperated surgicalsystem that can receive the transmission 4700 and manipulate thetransmission 4700 to perform various surgical operations. In otherembodiments, the drive device can be an assembly system that can receiveand manipulate the transmission 4700 to perform various assemblyoperations.

The first capstan assembly 4710 includes a shaft that can bemotor-driven to rotate about a capstan axle. The rotating shaft includesa portion about which an end portion of the first cable 4420 is wrapped.Thus, when the first capstan assembly 4710 rotates in a first direction,the first cable 4420 can be moved proximally (i.e., can be pulled inwardor wrapped about the rotating shaft), and when the first capstanassembly 4710 rotates in a second direction, the first cable 4420 can bemoved distally (i.e., can be payed-out or unwrapped from the rotatingshaft). In a similar manner, the second capstan assembly 4720 includes ashaft about which an end portion of the second cable 4430 is wrapped,the third capstan assembly 4730 includes a shaft about which an endportion of the third cable 4440 is wrapped, and the fourth capstanassembly 4740 includes a shaft about which an end portion of the fourthcable 4450 is wrapped. Referring to FIG. 11, the arrangement of thecapstan assemblies and the cable guide 4800 defines a cable path foreach of the cables. Through these cable paths, the cables are routedfrom their respective capstan assembly into the shaft 4410.

The roll actuator 4750 includes a shaft that can be motor-driven torotate about an axle. The rotating shaft includes a gear that mesheswith a shaft gear 4755 (see FIG. 17) coupled to the shaft 4410. Thus,when the roll actuator 4750 rotates in a first direction, the shaft gear4755 (and thus the shaft 4410) can be rotated in a first direction, andwhen the roll actuator 4750 rotates in a second direction, the shaftgear 4755 can be rotated in a second direction. The rotation of theshaft about the shaft axis (which functions as a roll axis; the termroll is arbitrary) is shown by the arrow DD in FIGS. 11 and 17.

The cable guide 4800 includes a cable cover 4860 and is coupled to theupper housing 4765 of the chassis 4760. Specifically, the cable guide4800 and the cable cover 4860 are coupled to the upper housing 4765 bytwo screws. In other embodiments, the cable guide 4800 and the cablecover 4860 can be coupled to the upper housing 4765 by any suitablemechanism (e.g., adhesive, heat weld, or the like). For example, in someembodiments, the cable cover 4860 can be coupled to the cable guide 4800via screws, and the cable guide 4800 can be coupled to the upper housing4765 by an adhesive. The cable guide 4800 includes an inner surface 4820that defines a shaft opening 4821. As shown in FIG. 17, the shaftopening 4821 opens into the passageway 4413 of the shaft 4410. Moreover,although shown as being noncircular, the shaft opening 4821 can have anysuitable shape (e.g., circular, oblong, or elliptical).

The cable guide 4800 includes a first guide groove 4831, a second guidegroove 4832, a third guide groove 4833, and a fourth guide groove 4834.The first cable 4420 is routed within the first guide groove 4831,through the shaft opening 4821, and towards the shaft passageway. Thefirst guide groove 4831 is defined by a first guide surface 4841 anddefines a first guide center line (not identified). The first guidesurface 4841 includes a first bend portion 4846 transitioning from thefirst guide groove 4831 into the shaft opening 4821. The first bendportion 4846 is characterized by a first bend radius about a first bendaxis (the first bend radius and the first bend axis are not identified,but are like the bend radius R₁ and the bend axis AB₁ described abovewith respect to the cable guide 3800). The second cable 4430 is routedwithin the second guide groove 4832, through the shaft opening 4821, andtowards the shaft passageway. The second guide groove 4832 is defined bya second guide surface 4842, and defines a second guide center line (notidentified). The second guide surface 4842 includes a second bendportion 4847 transitioning from the second guide groove 4832 into theshaft opening 4821. The second bend portion 4847 is characterized by asecond bend radius about a second bend axis (the second bend radius andthe second bend axis are not identified, but are like the bend radius R₂and the bend axis AB₂ described above with respect to the cable guide3800). The third cable 4440 is routed within the third guide groove4833, through the shaft opening 4821 and towards the shaft passageway.The third guide groove 4833 is defined by a third guide surface 4843,and defines a third guide center line (not identified). The third guidesurface 4843 includes a third bend portion 4848 transitioning from thethird guide groove 4833 into the shaft opening 4821. The third bendportion 4848 is characterized by a third bend radius about a third bendaxis (the third bend radius and the third bend axis are not identified,but are like the bend radii and the bend axes described above withrespect to the cable guide 3800). The fourth cable 4450 is routed withinthe fourth guide groove 4834, through the shaft opening 4821 and towardsthe shaft passageway. The fourth guide groove 4834 is defined by afourth guide surface 4844, and defines a fourth guide center line (notidentified). The fourth guide surface 4844 includes a fourth bendportion 4849 transitioning from the fourth guide groove 4834 into theshaft opening 4821. The fourth bend portion 4849 is characterized by afourth bend radius about a fourth bend axis (the fourth bend radius andthe fourth bend axis are not identified, but are like the bend radii andthe bend axes described above with respect to the cable guide 3800).

As shown in FIGS. 13 and 14, the first guide groove 4831, the secondguide groove 4832, the third guide groove 4833, and the fourth guidegroove 4834 are splayed outward from the shaft opening 4821. Similarlystated, the guide grooves are spread out apart from the shaft opening4821. Although not identified in FIGS. 13 and 14, the guide grooves candefine any suitable splay angle between them (similar to the splay angleθ described above with reference to the cable guide 2800). For example,the splay angle between adjacent guide grooves can be, for example,between 5 degrees and 60 degrees, between 10 degrees and 45 degrees, orbetween 15 degrees and 30 degrees. Additionally, the bend axes can benonparallel to any of the other bend axes. For example, the first bendaxis is nonparallel to the second bend axis, the third bend axis, andthe fourth bend axis. This arrangement allows the guide grooves to besplayed outward from the shaft opening 4821, as described above. Allfour of the bend axes, however, need not be nonparallel to each of theother bend axes. For example, in some embodiments, the second bend axisand the third bend axis can be parallel.

In some embodiments, at least one bend axis can be offset from amounting surface of the cable guide (not shown) by a different distancethan an offset distance from other of the bend axes. For example, asdescribed above with respect to the cable guide 3800, in someembodiments, the first bend portion 4846 can be positioned higher than(relative to the shaft 4410) than the second bend portion 4847 (or otherof the bend portion). In other embodiments, the first bend portion 4846can be positioned closer towards the shaft center line CL_(SH) than thesecond bend portion 4847 (or other of the bend portions). In thismanner, the first cable 4420, the second cable 4430, the third cable4440, and the fourth cable 4450 can be routed into the desired positionwithin the shaft opening 4821. Specifically, the cables can bepositioned within the shaft passageway spaced apart from the shaftcenter line and at different radial or circumferential positions withinthe shaft passageway. This arrangement can reduce the likelihood thatthe cables will become entangled with (e.g., twisted about) each otherwithin shaft 4410. For example, this arrangement facilitateslow-friction operation during roll of the shaft 4410 by maintaining thecables within the shaft 4410 in their desired locations.

Although the transmission 4700 is shown and described as includingcapstan assemblies, in other embodiments, a transmission or aninstrument can include any suitable number of capstan assemblies orcables. For example, FIGS. 18-20 are various views of a transmission5700, according to an embodiment. The transmission 5700 can be used inany suitable instrument. The instrument, the transmission 5700, or anyof the components therein are optionally parts of a surgical assemblythat performs minimally invasive surgical procedures, and which caninclude a manipulator unit, a series of kinematic linkages, a series ofcannulas, or the like. The instrument (and any of the instrumentsdescribed herein) can be used in any suitable surgical system, such asthe MIRS system 1000 shown and described above.

Referring to FIG. 18, the instrument includes a first cable pair 5420(which functions as a tension member) and a second cable pair 5440(which functions as a tension member). The first cable pair 5420includes a cable portion 5423 and a cable portion 5433. A proximal endof the first cable pair 5420 is wrapped about the first capstan assembly5710, as described below. A distal end of the first cable pair 5420 iscoupled to and actuates a wrist or an end effector (not shown). Thesecond cable pair 5440 includes a cable portion 5443 and a cable portion5453. A proximal end of the second cable pair 5440 is wrapped about thesecond capstan assembly 5720, as described below. A distal end of thesecond cable pair 5440 is coupled to and actuates a wrist or an endeffector (not shown). The instrument 5400 is configured such thatmovement of the cable pairs can produce rotation of a wrist assembly(i.e., pitch rotation), yaw rotation of an end effector, grip rotationof the tool members of the end effector about the yaw axis, or anycombination of these movements.

The transmission 5700 includes a chassis 5760, a first capstan assembly5710, a second capstan assembly 5720, and a cable guide 5800. Thechassis 5760 (which functions as a housing) provides the structuralsupport for mounting and aligning the components of the transmission5700. For example, as shown in FIG. 18, the chassis 5760 defines anopening within which the proximal end portion 5411 of the shaft 5410 ismounted, and multiple openings within which the capstan assemblies aremounted. The shaft 5410 can be any suitable elongated shaft that couplesthe wrist assembly (not shown) and the end effector (not shown) to thetransmission 5700. Specifically, the shaft 5410 includes a proximal endportion 5411 that is coupled to the chassis 5760. The shaft 5410 definesat least one passageway through which the cable portion 5423, the cableportion 5433, the cable portion 5443, the cable portion 5453, and othercomponents (e.g., energized electrical wires, ground wires, or the like,not shown) can be routed from the transmission 5700 towards the wristassembly.

The first capstan assembly 5710 includes a shaft that can bemotor-driven to rotate about a capstan axle. The rotating shaft includesa portion about which an end portion of the first cable 5420 is wrapped.Thus, when the first capstan assembly 5710 rotates in a first direction,the cable portion 5423 can be moved proximally (i.e., can be pulledinward or wrapped about the rotating shaft), and the cable portion 5433can be moved distally (i.e., can be payed-out or unwrapped from therotating shaft). The movement of the first cable pair 5420 can bereversed by changing the direction of rotation of the first capstanassembly 5710. In a similar manner, the second capstan assembly 5720includes a shaft about which an end portion of the second cable pair5440 is wrapped. Thus, when the second capstan assembly 5720 rotates ina first direction, the cable portion 5443 can be moved proximally (i.e.,can be pulled inward or wrapped about the rotating shaft), and the cableportion 5453 can be moved distally (i.e., can be payed-out or unwrappedfrom the rotating shaft). The movement of the second cable pair 5440 canbe reversed by changing the direction of rotation of the second capstanassembly 5720. Referring to FIG. 18, the arrangement of the capstanassemblies and the cable guide 5800 defines a cable path for each of thecables. Through these cable paths, the cables are routed from theirrespective capstan assembly into the shaft 5410.

The cable guide 5800 includes a stiffening rib 5835 and is coupled tothe chassis 5760. The cable guide 5800 can be coupled to the chassis5760 by any suitable mechanism (e.g., adhesive, heat weld, or the like).The stiffening rib 5835 can stiffen the overall structure of the cableguide 5800, thereby limiting the likelihood that the cable guide 5800will detach from (or rotate relative to) the chassis 5760. The cableguide 5800 includes an inner surface 5820 that defines a shaft opening5821. The shaft opening 5821 opens into the passageway of the shaft5410. Moreover, although shown as being noncircular, the shaft opening5821 can have any suitable shape (e.g., circular, oblong, orelliptical).

The cable guide 5800 includes a first guide groove 5831, a second guidegroove 5832, a third guide groove 5833, and a fourth guide groove 5834.The first cable portion 5423 is routed within the first guide groove5831, through the shaft opening 5821, and towards the shaft passageway.The first guide groove 5831 is defined by a first guide surface 5841 anddefines a first guide center line (not identified). Like the first guidesurface 4841 described above, the first guide surface 5841 includes afirst bend portion transitioning from the first guide groove 5831 intothe shaft opening 5821. The second cable portion 5433 is routed withinthe second guide groove 5832, through the shaft opening 5821, andtowards the shaft passageway. The second guide groove 5832 is defined bya second guide surface 5842 and defines a second guide center line (notidentified). Like the second guide surface 4842 described above, thesecond guide surface 5842 includes a second bend portion transitioningfrom the second guide groove 5832 into the shaft opening 5821. The thirdcable portion 5443 is routed within the third guide groove 5833, throughthe shaft opening 5821, and towards the shaft passageway. The thirdguide groove 5833 is defined by a third guide surface 5843 and defines athird guide center line (not identified). Like the third guide surface4843 described above, the third guide surface 5843 includes a third bendportion transitioning from the third guide groove 5833 into the shaftopening 5821. The fourth cable portion 5453 is routed within the fourthguide groove 5834, through the shaft opening 5821, and towards the shaftpassageway. The fourth guide groove 5834 is defined by a fourth guidesurface 5844 and defines a fourth guide center line (not identified).Like the fourth guide surface 4844 described above, the fourth guidesurface 5844 includes a fourth bend portion transitioning from thefourth guide groove 5834 into the shaft opening 5821.

As shown in FIG. 19, the first guide groove 5831, the second guidegroove 5832, the third guide groove 5833, and the fourth guide groove5834 are splayed outward from the shaft opening 5821. Similarly stated,the guide grooves are spread out apart from the shaft opening 5821.Although not identified in FIG. 19, the guide grooves can define anysuitable splay angle between them (similar to the splay angle θdescribed above with reference to the cable guide 2800). For example,the splay angle between adjacent guide grooves can be, for example,between 5 degrees and 60 degrees, between 10 degrees and 45 degrees, orbetween 15 degrees and 30 degrees. Additionally, the bend axes can benonparallel to any of the other bend axes. For example, the first bendaxis is nonparallel to the second bend axis, the third bend axis, andthe fourth bend axis. This arrangement allows the guide grooves to besplayed outward from the shaft opening 5821, as described above. Allfour of the bend axes, however, need not be nonparallel to each of theother bend axes. For example, in some embodiments, the second bend axisand the third bend axis can be parallel.

In some embodiments, any of the cable guides described herein can beconstructed from separate components that are assembled to form thecable guide. For example, FIGS. 21-23 are various views of atransmission 6700, according to an embodiment. The transmission 6700 canbe used in any suitable instrument and in any suitable surgical system,such as the MIRS system 1000 shown and described above. The instrumentincludes a first cable pair 6420 (which functions as a tension member)and a second cable pair 6440 (which functions as a tension member). Thefirst cable pair 6420 includes a cable portion 6423 and a cable portion6433. A proximal end of the first cable pair 6420 is wrapped about thefirst capstan assembly 6710, as described below. A distal end of thefirst cable pair 6420 is coupled to and actuates a wrist or an endeffector (not shown). The second cable pair 6440 includes a cableportion 6443 and a cable portion 6453. A proximal end of the secondcable pair 6440 is wrapped about the second capstan assembly 6720, asdescribed below. A distal end of the second cable pair 6440 is coupledto and actuates a wrist or an end effector (not shown). The instrument6400 is configured such that movement of the cable pairs can producerotation of a wrist assembly (i.e., pitch rotation), yaw rotation of anend effector, grip rotation of the tool members of the end effectorabout the yaw axis, or any combination of these movements.

The transmission 6700 includes a chassis 6760, a first capstan assembly6710, a second capstan assembly 6720, and a cable guide 6800. Thechassis 6760 (which functions as a housing) provides the structuralsupport for mounting and aligning the components of the transmission6700. For example, as shown in FIG. 21, the chassis 6760 is coupled tothe proximal end portion of the shaft 6410. The shaft 6410 can be anysuitable elongated shaft that couples the wrist assembly (not shown) andthe end effector (not shown) to the transmission 6700. The shaft 6410defines at least one passageway through which the cable portion 6423,the cable portion 6433, the cable portion 6443, the cable portion 6453,and other components (e.g., energized electrical wires, ground wires, orthe like, not shown) can be routed from the transmission 6700 towardsthe wrist assembly.

The first capstan assembly 6710 includes a shaft that can bemotor-driven to rotate about a capstan axle. The rotating shaft includesa portion about which an end portion of the first cable 6420 is wrapped.Thus, when the first capstan assembly 6710 rotates in a first direction,the cable portion 6423 can be moved proximally (i.e., can be pulledinward or wrapped about the rotating shaft), and the cable portion 6433can be moved distally (i.e., can be payed-out or unwrapped from therotating shaft). The movement of the first cable pair 6420 can bereversed by changing the direction of rotation of the first capstanassembly 6710. In a similar manner, the second capstan assembly 6720includes a shaft about which an end portion of the second cable pair6440 is wrapped. Thus, when the second capstan assembly 6720 rotates ina first direction, the cable portion 6443 can be moved proximally (i.e.,can be pulled inward or wrapped about the rotating shaft), and the cableportion 6453 can be moved distally (i.e., can be payed-out or unwrappedfrom the rotating shaft). The movement of the second cable pair 6440 canbe reversed by changing the direction of rotation of the second capstanassembly 6720. Referring to FIG. 21, the arrangement of the capstanassemblies and the cable guide 6800 defines a cable path for each of thecables. Through these cable paths, the cables are routed from theirrespective capstan assembly into the shaft 6410.

The cable guide 6800 includes a top portion 6830 and is coupled to thechassis 6760. The cable guide 6800 can be coupled to the chassis 6760 byany suitable mechanism (e.g., adhesive, heat weld, or the like). Thecable guide 6800 includes an inner surface 6820 that defines a shaftopening 6821. The shaft opening 6821 opens into the passageway of theshaft 6410. Moreover, although shown as being noncircular, the shaftopening 6821 can have any suitable shape (e.g., circular, oblong, orelliptical).

The cable guide 6800 includes a first guide groove 6831, a second guidegroove 6832, a third guide groove 6833, and a fourth guide groove 6834.The first cable portion 6423 is routed within the first guide groove6831, through the shaft opening 6821, and towards the shaft passageway.The first guide groove 6831 is defined by a first guide surface and afirst pin 6846. The first pin 6846 is pressed into the top portion 6830and provides a first bend portion transitioning from the first guidegroove 6831 into the shaft opening 6821. The second cable portion 6433is routed within the second guide groove 6832, through the shaft opening6821, and towards the shaft passageway. The second guide groove 6832 isdefined by a second guide surface and a second pin 6847. The second pin6847 is pressed into the top portion 6830 and provides a second bendportion transitioning from the second guide groove 6832 into the shaftopening 6821. The third cable portion 6443 is routed within the thirdguide groove 6833, through the shaft opening 6821, and towards the shaftpassageway. The third guide groove 6833 is defined by a third guidesurface and a third pin 6848. The third pin 6848 is pressed into the topportion 6830 and provides a third bend portion transitioning from thethird guide groove 6833 into the shaft opening 6821. The fourth cableportion 6453 is routed within the fourth guide groove 6834, through theshaft opening 6821, and towards the shaft passageway. The fourth guidegroove 6834 is defined by a fourth guide surface and a fourth pin 6849.The fourth pin 6849 is pressed into the top portion 6830 and provides afourth bend portion transitioning from the fourth guide groove 6834 intothe shaft opening 6821.

As shown in FIG. 22, the first guide groove 6831, the second guidegroove 6832, the third guide groove 6833, and the fourth guide groove6834 are splayed outward from the shaft opening 6821. Similarly stated,the guide grooves are spread out apart from the shaft opening 6821.Although not identified in FIG. 22, the guide grooves can define anysuitable splay angle between them (similar to the splay angle θdescribed above with reference to the cable guide 2800). For example,the splay angle between adjacent guide grooves can be, for example,between 5 degrees and 60 degrees, between 10 degrees and 45 degrees, orbetween 15 degrees and 30 degrees. Additionally, the bend axes can benonparallel to any of the other bend axes. For example, the first bendaxis is nonparallel to the second bend axis, the third bend axis, andthe fourth bend axis. This arrangement allows the guide grooves to besplayed outward from the shaft opening 6821, as described above. Allfour of the bend axes, however, need not be nonparallel to each of theother bend axes. For example, in some embodiments, the second bend axisand the third bend axis can be parallel.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Where methods and/or schematics described above indicatecertain events and/or flow patterns occurring in certain order, theordering of certain events and/or operations may be modified. While theembodiments have been particularly shown and described, it will beunderstood that various changes in form and details may be made.

For example, any of the instruments described herein (and the componentstherein) are optionally parts of a surgical assembly that performsminimally invasive surgical procedures, and which can include amanipulator unit, a series of kinematic linkages, a series of cannulas,or the like. Thus, any of the instruments described herein can be usedin any suitable surgical system, such as the MIRS system 1000 shown anddescribed above. Moreover, any of the instruments shown and describedherein can be used to manipulate target tissue during a surgicalprocedure. Such target tissue can be cancer cells, tumor cells, lesions,vascular occlusions, thrombosis, calculi, uterine fibroids, bonemetastases, adenomyosis, or any other bodily tissue. The presentedexamples of target tissue are not an exhaustive list. Moreover, a targetstructure can also include an artificial substance (or non-tissue)within or associated with a body, such as for example, a stent, aportion of an artificial tube, a fastener within the body or the like.

For example, although the guide grooves are shown and described hereinas being linear, in other embodiments any of the guide grooves describedherein can be curved (i.e., can have a curved guide center line).

Any of the tension members described herein can be formed as a cablemade of Tungsten or stainless steel to provide sufficient strength,bendability and durability. In some embodiments, cables can beconstructed from multiple braids of fine wire, to provide strength andresiliency. In some embodiments, cables can be made from 150 to 350braids of 0.0007 inch to 0.001 inch (0.01778 mm to 0.0254 mm) diametertungsten wire providing cables with outer diameters of 0.014 inches to0.018 inches (0.3556 mm to 0.4572 mm). Moreover, although shown anddescribed as guiding cables, any of the guide structures describedherein can be adapted for use with any suitable tension member. Forexample, in some embodiments, the transmission 2700 (and any of thetransmissions or instruments described herein) can include a tensionmember having any suitable cross-sectional shape. For example, in someembodiments, the transmission 2700 (and any of the transmissions orinstruments described herein) can include a tension band, of the typesshown and described in U.S. Patent Application No. 62/598,620 (filedDec. 14, 2017), entitled “Medical Tools Having Tension Bands,” which isincorporated herein by reference in its entirety.

In some embodiments, any of the guide surfaces described herein can becoated, treated or otherwise produced to have a low-friction surface.For example, in some embodiments, any of the guide surfaces can becharacterized by a coefficient of friction of less than 0.1. In someembodiments, any of the guide surfaces can be coated with afriction-reducing composition.

In some embodiments, any of the guide surfaces described herein can beconstructed from a low-friction material that reduces the frictionallosses between the cables and the cable guide. For example, in someembodiments, any of the cable guides described herein can bemonolithically constructed from a low friction material. Such materialscan include, for example, polyether ether ketone (PEEK) filled with atleast one of a glass material or polytetrafluoroethylene (PTFE). In someembodiments, any of the cable guides described herein can bemonolithically constructed from any suitable material (e.g., polymer,metal, composite) and can include a friction-reducing coating on theguide surfaces. In yet other embodiments, any of the cable guidesdescribed herein can be constructed from separate components that areassembled to form the cable guide.

Although the cable guide 4800 is shown as being constructed separatelyfrom and attached to the upper housing 4765, in other embodiments, thecable guide and the upper housing can be monolithically constructed.

Although various embodiments have been described as having particularfeatures and/or combinations of components, other embodiments arepossible having a combination of any features and/or components from anyof embodiments as discussed above. Aspects have been described in thegeneral context of medical devices, and more specifically surgicalinstruments, but inventive aspects are not necessarily limited to use inmedical devices.

For example, although the first guide path 2831 is described above ashaving a bend angle β (i.e., between the first guide center line CL₁ andthe opening center line CL_(OP)) of greater than 45 degrees, greaterthan 60 degrees, or greater than 75 degrees, in other embodiments, anyof the guide paths described here can have a bend angle like thatdescribed for the first guide path 2831. For example, any of the guidepaths of the cable guide 4800 can have a bend angle of greater than 45degrees, greater than 60 degrees, or greater than 75 degrees.

What is claimed is:
 1. An apparatus, comprising: a shaft of a medicalinstrument, a first cable, a second cable, and a cable guide; the cableguide comprising a mounting surface, an inner surface, a first guidesurface, and a second guide surface; the inner surface defining a shaftopening into a shaft passageway defined by the shaft; the first guidesurface comprising a first bend portion transitioning to the innersurface, the first bend portion being characterized by a first bendradius about a first bend axis, the first bend axis being offset fromthe mounting surface by a first offset distance; the second guidesurface comprising a second bend portion transitioning to the innersurface, the second bend portion being characterized by a second bendradius about a second bend axis, the second bend axis being offset fromthe mounting surface by a second offset distance, the second offsetdistance being different than the first offset distance; the first cablebeing routed along the first guide surface, around the first bendportion, and through the shaft opening; and the second cable beingrouted along the second guide surface, around the second bend portion,and through the shaft opening.
 2. The apparatus of claim 1, wherein thefirst bend portion defines a first bend angle of more than 60 degrees.3. The apparatus of claim 1, wherein: a first guide groove is defined inthe first guide surface; a second guide groove is defined in the secondguide surface; the first cable is routed within the first guide groove;and the second cable is routed within the second guide groove.
 4. Theapparatus of claim 3, wherein a first center line of the first guidegroove is nonparallel to a second center line of the second guidegroove.
 5. The apparatus of claim 3, wherein the first guide groove andthe second guide groove are splayed outward from the shaft opening. 6.The apparatus of claim 1, further comprising: a housing coupled to theshaft; and the mounting surface comprises a protrusion that engages thehousing and aligns the shaft opening and the shaft passageway.
 7. Theapparatus of claim 1, further comprising: a pin coupled to the cableguide, the pin comprising an outer surface; and the first bend portionof the first guide surface is a portion of the outer surface of the pin.8. The apparatus of claim 1, wherein the cable guide, the first guidesurface, and the second guide surface are monolithically constructed. 9.The apparatus of claim 1, wherein: a central portion of the first cableis routed within the passageway of the shaft; a central portion of thesecond cable is routed within the passageway of the shaft; and the firstbend portion and the second bend portion are positioned such that thecentral portion of the first cable and the central portion of the secondcable are each spaced apart from a shaft center line of the passageway.10. The apparatus of claim 9, wherein: the central portion of the firstcable is at a first position on a circumference defined around the shaftcenter line of the passageway; the central portion of the second cableis at a second position on the circumference; and the second position isdifferent from the first position.
 11. The apparatus of claim 1, furthercomprising: a cover coupled to the cable guide, the cover beingpositioned over the shaft opening.
 12. An apparatus, comprising: a shaftof a medical instrument, a housing coupled to the shaft, a cable guide,a first cable, and a second cable; the shaft comprising a shaft centerline, a shaft passageway being defined by the shaft; the cable guidecomprising an inner surface, a mounting surface, a first guide surface,and a second guide surface; the inner surface defining a shaft openinginto the shaft passageway; the mounting surface comprising a protrusionthat engages the housing and aligns the shaft opening and the shaftpassageway; the first guide surface comprising a first bend portiontransitioning to the inner surface, the first bend portion being at afirst position with reference to the shaft center line; the second guidesurface comprising a second bend portion transitioning to the innersurface, the second bend portion being at a second position withreference to the shaft center line, the second position different thanthe first position; the first cable being routed along the first guidesurface, around the first bend portion, and through the shaft opening;the second cable being routed along the second guide surface, around thesecond bend portion, and through the shaft opening; and the first cableand the second cable being splayed outward from the shaft opening. 13.The apparatus of claim 12, wherein: a central portion of the first cableis routed within the passageway of the shaft; a central portion of thesecond cable is routed within the passageway of the shaft; and the firstposition of the first bend portion and the second position of the secondbend portion are such that the central portion of the first cable andthe central portion of the second cable are each spaced apart from theshaft center line.
 14. The apparatus of claim 13, wherein: the centralportion of the first cable is at a first circumferential position on acircumference defined around the shaft center line; the central portionof the second cable is at a second circumferential position on thecircumference; and the second circumferential position is different fromthe first circumferential position.
 15. The apparatus of claim 13,wherein: the central portion of the first cable is at a first radialposition with reference to the shaft center line; the central portion ofthe second cable is at a second radial position with reference to theshaft center line; and the second radial position is different from thefirst radial position.
 16. The apparatus of claim 12, wherein: the firstbend portion is at a first height above the shaft opening; the secondbend portion is at a second height above the shaft opening; and thesecond height is different from the first height.
 17. The apparatus ofclaim 12, wherein: a first guide groove is defined in the first guidesurface; a second guide groove is defined in the second guide surface;the first cable is routed within the first guide groove; and the secondcable is routed within the second guide groove.
 18. The apparatus ofclaim 12, wherein the first bend portion defines a first bend angle ofmore than 60 degrees.
 19. The apparatus of claim 12, further comprising:a cover coupled to the cable guide, the cover being positioned over theshaft opening.